NEW YORK (NBC News) – Investigators for the Department of Veterans Affairs are fanning out nationwide to find out how many vets suffered due to delayed medical care, and if any knowledge of inferior treatment was covered up by V.A. officials.

The probe of delayed care is starting at the Veterans Affairs hospitals in Phoenix, Arizona and Fort Collins, Colorado, where dozens of patients are alleged to have died while waiting for treatment.

Every V.A. hospital in the system, more than 150, will be audited.

Senator John McCain was in Arizona Friday to talk with veterans about the situation, which he called “unacceptable”.